Heritage Building Surveying & Information Modelling – a HBIM approach

Company Background

Murphy Surveys was established in 1983 by Peter Murphy; a visionary of his time in the field of

surveying. Peter believed that the future of the industry lay in technological progression and to

deliver a more efficient and quality-focused service.

Now 33 years later, Murphy Surveys has offices in Kildare, Dublin, Cork, Belfast, London, Northwich

and Scotland. Employing more than 200 staff and offering world-class solutions globally to public and

private sector clients, including government bodies and blue chip companies. MSL have grown year

on year, because of its commitment to innovation and striving to exceed our clients’ needs. The

continuing adoption of these core principles are a cornerstone of the development of BIM and HBIM

methodologies within the company.

Current BIM standards:

There are many BIM standards and guidelines internationally. While the UK has a mandated BIM

requirement on government projects we do not have such a mandate in Ireland currently. However,

many businesses here work in the UK also and with close proximity we have tended to adopt the UK

standards and the same can be said with BIM. The BIM standard currently is a PAS (Publically

Accessible Standard), namely, PAS 1192 Parts 2 & 3 with Parts 4 and 5 very recent additions to this.

PAS 1192 : 2 is the Specification for information management for the capital phase of construction

projects using building information modelling (BIM). Part 3 concerns information management for the

operational phase of assets using BIM.

While these standards apply quite easily to design projects and subsequently to operational projects,

Surveyors have the task of compiling data on old and existing projects with little pre-existing

information, and turning these into ‘hit the ground running’ BIM projects. The standards cover the

requirements for the main design teams on these projects but does not clarify the roles and

requirements of sub -contractors, or how groups of sub-contractors can work together.

The fact is, as a surveyor, we do not simply take measurements with total stations anymore. Using

laser scanning techniques and UAV (unmanned aerial vehicles) we can gather massive amounts of

data on whole urban sites very quickly and on difficult areas such as inaccessible rooftops, while

displaying this information can be done in a variety of ways that many clients aren’t aware of. It has

resulted in MSL developing in house workflows for delivering BIM that encompasses many software

types, and uses many delivery options from local to cloud storage and web viewing options where we

can give data to clients without the need for them to store it themselves. A survey is no longer a set of

drawings but also a model environment and an online portal allowing 360 degree navigation and

dimensioning of realistic laser scans similar to a Google Street View scene only with added functions.

Using these techniques MSL deliver high quality Survey BIMs that not only comply with current PAS

standards but seeks to set its own standard when it comes to BIM offerings and value for a client.

Project Brief:

MSL were appointed by our Client to

undertake a measured building survey of a

historical site within Dublin City Centre. The

project involved high quality surveys of areas

of most concern with surrounding buildings

and topography surveyed as context to

different degrees. Our BIM survey would be

used as a starting point and background for a

design BIM process. Overall the project area

covered c. 20,000 square meters consisting of dense urban heritage buildings approx. 4 storeys high

for much of it. The environment was extremely complex and intricate with basements featuring a

maze of different barrel vaulted ceilings, aswell as floors and walls that were sagging and warping to a

high degree in many different planes and sections. Varying constructions also made it hard to

understand the spaces easily on a project this size.

Staff Involvement:

Alan Halpin B.Eng Civil Eng., BIM manager (Ireland), has a wide range of experience in the construction

industry from Civil engineering to architectural and sustainable design. He also has qualifications in

Quality Engineering and lean practices and brings this added value and experience to Survey BIM

projects. He has been involved in BIM, covering small to large scale design and surveying projects

intensively for over 6 years, spanning various countries and disciplines in Australia, UK and Ireland. He

is passionate about BIM and the value it brings to any project. He is also an advocate for BIM

standards and procedures and the overall adoption of these in the mainstream Irish market.

Stuart McCann, BIM Technician. Stuart graduated from Institute of Technology Carlow in 2011 as an

architectural technician having completed his final year thesis using Autodesk Revit. Since then he has

worked with Murphy Surveys BIM/Scanning department on a wide variety of projects from residential

to large scale land and pharmaceutical surveys and brings much experience in both office and site

based surveying. This combination of architecture and site surveying & scanning provides valuable

skills for BIM Surveys as the information needs and data capture of a BIM project can be different to

a traditional survey. Knowing the best way to get this data is massively important to all BIM projects.

Alex Macovei, BIM Technician | R&D . Alex graduated from University of Brasov, Romania in 2013

and has a bachelor degree in Geodesic Engineering. He has worked with Murphy Surveys since

February 2014 working on complex Data centre facilities and data management and has developed

customised workflows that allow better data integration to BIM and 3D modelling environments. He

has also carved out a position within a Research and Development role where he tests and

implements new and emerging technologies and softwares in BIM data capture areas aswell as the

UAV and VR/Augmented Reality space.

Objectives:

The aim was to provide laser scan surveys and an accurate BIM model of the site and surroundings

that could be used as part of a BIM design and retrofit project of the heritage site in question. This

model would need to be set up in accordance with PAS 1192 and would require information such as

material changes and detail items such as cornicing, radiators, sills, and site surrounding hardscape ,

and set up as linked separated files which could be used in a variety of ways for the BIM design

project.

Challenges:

The whole site proved challenging

to get access at appropriate times.

Many areas were off limits or were

extremely difficult to get access to,

while other areas were hard to

physically survey such as rooftops

due to poor access, dangerous

conditions on the rooftops and

poor stability for laser scanner

tripod set up. Unprotected edge

and parapets made it difficult to

survey certain roof faces while moving between properties on rooftops became hazardous. So many

of the adjacent buildings had different access requirements, and this resulted in many trips back to

site, and delays in gathering relevant survey data for such areas.

Innovative Use of BIM:

The nature of BIM tends to be consistency of standardised objects and cost efficiency, so a heritage

site whereby every second floor is sagging far beyond the desired model tolerances, in excess of

120mm over 5m spans in multiple directions in many cases, demands a customised approach. This

approach meant that rather than simply modelling best fit scenarios, we were aware that many other

subcontractors would use our data based on CAD exported sections only, so such floors were

modelled efficiently and accounted for the main sagging and deviations using sub-points for

simplicity, while other minor deviations were noted in custom deviation parameter fields and survey

comments fields for scheduling and tracking. It allowed us to maintain the connections and visibility

of native BIM objects along with provision of important notes and comments available for data

extraction, scheduling and filtered views. CAD based sub contractors would still able to use our data in

an improved manner rather than if we followed standard BIM modelling practices meant for design

purposes ie. using standard regular components in a best fit manner.

Other challenges involved the staggering natures of the project site. Varying levels and adjacent

constructions were to be modelled and set up in plans and sections in one building file originally, this

was however revised once the nature of the site was better understood and captured in the laser

scans, so individual building pairs were created that were logically connected together and could be

turned on or off then in a master site file. Care was taken to not divide the site into too many

components as to become confusing when linked into other projects or for documentation purposes.

Opportunities for heritage recording are possible in this BIM environment while inventory and

schedules can be extracted quickly.

To improve the use of a hBIM for conservation needs and usability we inserted small spherical objects

into each room in the model at the survey scanner positions used originally to survey the site and

structures. These small floating objects contain a link url to a cloud stored 360 panorama image

recorded by the scanners which allows viewing of high quality detailed photographs that can be

panned 360 degrees with zoom functions to inspect the room spaces and site situation at time of

survey, enabling more detailed recording of architectural and heritage features of significance while

improving the integration of survey data into one point of access.

Placing these small spheres into relevant spaces allows any user to move between the model

environment and the associated 360 HQ panorama images quickly and efficiently from the correct

location and overcomes problems with navigating a separate folder of images with confusing naming

conventions and lack of ease in assessing where images relate to model points of views and positions.

Further to this, high quality images of individual architectural features can be linked to model

components easily through input of relevant url links to the appropriate parameter field in the

properties of the components for further recording opportunities within the same model.

Security of the images is protected by passwords which can be changed by the owner of the

information but allows permitted users of the model to view surveyed imagery tied to model objects.

Using the 360 imagery taken by personnel while carrying out laser scanning also allowed consistency

in tracking a complete set of images with scanner locations and data and also reducing time spent

collecting information such as separate photography and survey data collating trips.

Laser scan information is also linked into the models for viewing but the availability of high quality

imagery is a more convenient and lightweight solution in many cases for clients alongside a model file.

This method allows the client to gain a complete construction documentation set and visual record all

from one source in the model file and speeding up project understanding and communication of

survey information to stakeholders.

To model structure and spaces this was carried out by modelling direct to laser scan information

linked into the model environment. Laser scans are processed immediately after site collecting and

once registered are a complete point in time record of the 3D space and surrounding of the site. They

can be used instantly to measure and view the survey site before waiting for a model and other CAD

deliverables to be produced from the laser scan survey.

Below are Ortho Images with CAD overlay, produced from the laser scan data.

Laser scans are excellent health and safety tools that reduce the need to manually survey objects at

dangerous heights and locations and conditions. As a risk management tool this was ideal on a

complex site such as Parnell Square. Access and dereliction bring about their own risks and structural

safety concerns but using laser scans helped to mitigate this is most situations. The laser scan survey

and the final model itself provides an excellent 3D spatial understanding of the spaces concerned so

that trips to the site by related personnel can be reduced. Further 4D and 5D opportunities aswell as

clash detection between survey information and design information can be carried out downstream

by the client or design team thereby supporting the overall BIM process.

Collaboration and Communication:

Project progress meetings were held at key intervals prior to final delivery of survey models to assess

suitability, integrity, and method of model building techniques aswell as general progression of works.

Murphys met with key stakeholders involved on the project to ensure that all involved were kept up

to date and to agree best methods of modelling to suit the client and the employers information

requirements on the project.

Models also included custom 3D views where items containing comments specific to the survey were

filtered and highlighted for easier viewing and comment by the client when interrogating the model at

anytime allowing for further collaboration opportunities.

Interoperability:

In order to alleviate file formats differences Murphy Surveys produced a revit file deliverable aswell as

an IFC 2x3 Coordination view 2.0 format export of the files which were tested using Solibri before

submitting to the client for use in other software. Issues with any elements or materials in the

conversion process were communicated so as to allow a speedy resolution to any problems

encountered before final submissions.

Laser scan information was delivered in raw and processed formats where relevant for archiving

purposes while Colour ortho photography overlayed with CAD information was produced for external

and internal elevational sections of each room and space from the laser scan information. This was

delivered to client in a variety of formats including PDF for sharing and security aswell as traditional

CAD formats that the client had specified.

Finally, Model information has been uploaded to Autodesk a360 for sharing online to the client and

stakeholders at http://a360.co/2dbKkoE . Security has been controlled through sharing permissions

and downloading restrictions where needed but the aim is to share the model to users that do not

have required software for collaboration opportunities and interoperability purposes. The model can

be shared now online, inspected, cut and sectioned easily, aswell as measured and marked up and

shared to others for comment. The spherical objects hosting the 360 panorama images can be viewed

from inside the A360 environment through the associated URL links also, all through a web browser

only.

Use of International Standards:

The Project was modelled using Revit 2015 as the authoring tool. Before modelling however all

relevant BIM personnel on the project were familiar with and had experience working to standards

and specifications such as AEC (UK) BIM Protocols for Revit, PAS 1192-2:2013, LOD Specification 2015

as minimum aswell as best practice on complying with EIR, AIR, BEP and Supply chain model

responsibility matrix documents and so forth. All relevant documents relating to best practice

International BIM are stored on company servers in logical folder systems so that new BIM personnel

can access these while training or refreshing their knowledge of requirements and guidelines before

working on live projects. Building on these standards modelling approaches were defined to best suit

the client’s requirements while keeping to the spirit of model integrity, efficiency and information

usability within. Combining these approaches with surveyed real world information from a laser scan

was difficult in many cases on this heritage project as non standard approaches had to be adopted to

enable adequate information provision in cases.

The purpose of the BIM survey was critical here as decisions were made regarding usability of

standard components such as walls and floors and other architectural and structural elements in

terms of dimensioning accuracy versus parametric function and flexing within the model. Standard

elements were used where possible and customised modelling reduced where possible however in a

heritage project such as this where warping, bowing, sagging, deformation and damage are common

place and dimensioning is the key factor, modelling approaches were changed in order to describe

such information visually in a better way with regard still to efficient and compact model sizes and

behaviour and logical object and file naming according to BS 1192-2.

Outcomes and Results:

The outcome of this HBIM project was a survey BIM that met the client brief but also a HBIM

methodology that has provided us with a new understanding of how to approach large heritage

surveys in BIM formats. From quoting stage right through to deliverable options and model structures

/ techniques MSL have developed new procedures and methods for delivering High Quality hBIM’s at

this scale while demonstrating less than 5% tolerance from original modelling estimated time which is

excellent considering the challenges we faced on site. Survey observations and structural condition

notes were inputted to the models and further heritage recording is possible for asset and

conservation recording using 360 panorama images inserted by url links into floating model objects at

scanner locations. Other high quality images can be linked to individual model elements in the same

way further improving heritage opportunities and asset management or conservation workflows. BIM

Deliverables included IFC and Revit models, and high quality Laser scan files while other deliverables

included photographs and condition reports internally.

From this data animations and renderings were also possible (Watch Animation Here) as well as many

other downstream uses for ongoing BIM projects over the lifecycle of this complex site, using both

the scan and model information.

UAV information was not specified for this project but advances in the previous year mean that

MurphyUAV can now provide such services on projects this size and area much more easily as a

specialist service. Rooftop access outlined in this document would be much less of an issue and data

gathering significantly speeded up by using such data methods which can then be incorporated

directly into laser scan projects and BIM projects aswell. Surrounding context can be gathered very

quickly and easily and linked into Models once processed.

Excellence

The desire to excel is what pushes Murphy Surveys to innovate and develop high quality BIM and

HBIM surveys. Below are some of our accreditations and is the result of our hard work in this sector to

provide better surveys, better data.

Murphy Surveys through their unprecedented understanding of spatial data have adapted to ensure

that they remain at the fore of surveying in Ireland. Unlike many other companies operating in the

BIM sphere, all data acquisition is captured in house and processed thereafter. It is important to note

that Murphy Surveys are strategically placed to deliver survey information across Ireland and Britain,

supplying all of the data requirements for the emerging UAV sectors, and also for Asset Management,

Building Surveys, Hydrographical, Utility, Civil and Land Surveys all within a single BIM sphere. This

data can be used for traditional means and also for spatial coordination, orthographic elevations,

reporting, data extraction and many other uses.